SOME IMPROVISED APPARATUS SISTER MARY CASIMIR, R.S.M. Camden Catholic High School, Camden, New Jersey
MAXT and varied are the reasons whichmay prompt a stndent t o design and build a piece of scientific apparatus; many and varied are the choices he may make as to what he will build and how; and, indeed, many and varied are the reactions we teachers may experience upon sight of the finished products. In this school, some of the reasons which prompt our students to improvise, duplicate, and invent apparatus include the following. The youngsters may wish t o participate in a Science Fair, so they plan and build a piece of apparatus that mill be useful in the laboratory after the competition. Perhaps the Science Research Club wants to do some work which requires specialized apparatus, and, lacking the funds required to purchase it, they attempt t o duplicate it, patterning their product after a picture in a magazine or catalogue. Again, the student may be fascinated by some machine, process, or reaction, and thus may start his work from sheer interest. A fourth cause may be a desire t o build a model that the teacher can use in a demonstration for the science classes. Some of the useful pieces of apparatus that the students in our high school have constructed are described below. (1) Hand Centrifuge. This device, ( A ) in the illustration, was made from a discarded meat grinder which mas attached t o a small table built from scrap wood and pieces of iron found in a shop. The grinder was attached to a shaft which turns the head by means of a belt. The aluminum holders and glass centrifuge tubes were purchased from a supply house. This won a first award in the Philadelphia Science Fair. (2) pH Meter. This instrument ( B ) is the latest addition to our laboratory. The case houses three tubes, an amplifier, and a cell, which are connected t o the voltmeter (visible in the picture) which is in turn connected to the electrode assembly shown below. Plans for the model were made by the builder after considerable research on pH meters and some examination of schematic diagrams. This won a special award in the 1954 Philadelphia Science Fair. ( 3 ) Emulsifier. This useful piece of equipment, which serves very suitably as a shaker as well as an emulsifier, was also built for an exhibit. It consists of a small table t o which was attached a rectangular box containing four bottles (half-pint milk bottles) mounted on springs. This box is made t o move up and down as the handle is turned, thus causing the bottles t o vibrate and their contents to he emulsified or shaken, as the case may be. (1) Tin-can Planetarium. This article is useful as
a demonstration piccc in gcneral srience rlasses (if the room is dark enough). The builder got his idea from Watson's article in The Science Teacher.' As an exhibit this won a third award in the Philadelphia Science Fair. ( 5 ) Stirrer. A broken-down stirrer used in a drug store for making milk shakes was secured, reconditioned, mounted on a base, and put to work in the laboratory. (6) Cooling Box. The purpose of this device is to provide a cooling chamber for materials whose temperature we wish to keep below O°C. The box (an old pneumatic trough, small size) contains a mixture of acetone and dry ice and has a fitted top containing holes large enough to admit test tubes containing the experimental material. This article has the disadvantage, however, of needing constant attention because the mixture lasts only for a limited time. (7) Print Box. A member of the school Photography Club found it feasible to add this box to our collection. I t is fashioned as is any ordinary print box on the market. Two electric sockets are in the box, one on the side wall and one (for the red lamp) on the floor. When the plug is attached the red light goes on. A switch is provided on the side for the other lamp. (8) Apparatus for Sending Sound on a Beam of Light. This was erected primarily, of course, as an exhibit, but it is useful and interesting for demonstrations in science class as well. The materials used in this exhibit are: a radio, a flashlight, a photoelectric cell, and an amplifier. The entire setup is encased in a wooden frame which is covered with protective screening. It is arranged as follows: the flashlight is attached t o the audio output of the radio, encased on the right side of the exhibit box, and made to shine directly on the photo cell, which is connected t o an amplifier on the left side. Passing an opaque object through the beam of light causes variations in the sound. WATSON,F. G., The Science Teacher, 17, 180-83 (1950).
